Liam Olds has done a lot of invert surveys at this site, and had mentioned the presence of tufaceous springs - something I'd not seen on colliery spoil. We looked at a couple of these on the western side of the tip - they certainly look odd but we failed to find any unusual bryophyte species: only Didymodon tophaceus, Aneura pinguis, Cratoneuron filicinum and Bryum pseudotriquetrum were recorded on the tufa.
Elsewhere, we found a couple of patches of what looks like it might be Lophocolea semiteres growing on spoil under young birch - photos below. I'm not absolutely sure it's not L. heterophylla - some of the leaf tips are retuse but most are entire, and none are very notched. Photos below.
Most of the spoil was fairly species-poor but we did find small patches of Calliergonella lindbergii (photo below), Archidium alternifolium, Campyliadelphus chrysophyllus and Weissia brachycarpa var obliqua. The young willow and birch woodland was quite rich, with Rhytidiadelphus triquetrus and a good range of epiphytes.